Vibe Check MCP

This project is in maintenance mode. Active feature development has ended; only maintenance patches (security and bug fixes) are published. v2.9.0 is the latest maintenance release. The server remains fully functional. Community forks and contributions are welcome under the MIT license.

KISS overzealous agents goodbye. Plug & play agent oversight tool.

Based on research:
In our study agents calling Vibe Check improved success +27% and halved harmful actions -41%

_{Featured on PulseMCP “Most Popular (This Week)” • 5k+ monthly calls on Smithery.ai • research-backed oversight • STDIO + streamable HTTP transport}

Plug-and-play mentor layer that stops agents from over-engineering and keeps them on the minimal viable path — research-backed MCP server keeping LLMs aligned, reflective and safe.

Trusted by developers across MCP platforms and registries

Quickstart (npx)

Run the server directly from npm without a local installation. Requires Node >=20. Choose a transport:

Option 1 – MCP client over STDIO

npx -y @pv-bhat/vibe-check-mcp start --stdio

• Launch from an MCP-aware client (Claude Desktop, Cursor, Windsurf, etc.).
• [MCP] stdio transport connected indicates the process is waiting for the client.
• Add this block to your client config so it spawns the command:

{
  "mcpServers": {
    "vibe-check-mcp": {
      "command": "npx",
      "args": ["-y", "@pv-bhat/vibe-check-mcp", "start", "--stdio"]
    }
  }
}

Option 2 – Manual HTTP inspection

npx -y @pv-bhat/vibe-check-mcp start --http --port 2091

• curl http://127.0.0.1:2091/healthz to confirm the service is live.
• Send JSON-RPC requests to http://127.0.0.1:2091/mcp.

npx downloads the package on demand for both options. For detailed client setup and other commands like install and doctor, see the documentation below.

Recognition

• Featured on PulseMCP “Most Popular (This Week)” front page (week of 13 Oct 2025) 🔗
• Listed in Anthropic’s official Model Context Protocol repo 🔗
• Discoverable in the official MCP Registry 🔗
• Featured on Sean Kochel's Top 9 MCP servers for vibe coders 🔗

Table of Contents

• Quickstart (npx)
• What is Vibe Check MCP?
• Overview
• The Problem: Pattern Inertia & Reasoning Lock-In
• Key Features
• What's New
• Development Setup
• Release
• Usage Examples
• Adaptive Metacognitive Interrupts (CPI)
• Agent Prompting Essentials
• When to Use Each Tool
• Documentation
• Research & Philosophy
• Security
• Roadmap
• Contributors & Community
• FAQ
• Listed on
• Credits & License

What is Vibe Check MCP?

Vibe Check MCP keeps agents on the minimal viable path and escalates complexity only when evidence demands it. Vibe Check MCP is a lightweight server implementing Anthropic's Model Context Protocol. It acts as an AI meta-mentor for your agents, interrupting pattern inertia with Chain-Pattern Interrupts (CPI) to prevent Reasoning Lock-In (RLI). Think of it as a rubber-duck debugger for LLMs – a quick sanity check before your agent goes down the wrong path.

Overview

Vibe Check MCP pairs a metacognitive signal layer with CPI so agents can pause when risk spikes. Vibe Check surfaces traits, uncertainty, and risk scores; CPI consumes those triggers and enforces an intervention policy before the agent resumes. See the CPI integration guide and the CPI repo at https://github.com/PV-Bhat/cpi for wiring details.

Vibe Check invokes a second LLM to give meta-cognitive feedback to your main agent. Integrating vibe_check calls into agent system prompts and instructing tool calls before irreversible actions significantly improves agent alignment and common-sense. The high-level component map: docs/architecture.md, while the CPI handoff diagram and example shim are captured in docs/integrations/cpi.md.

The Problem: Pattern Inertia & Reasoning Lock-In

Large language models can confidently follow flawed plans. Without an external nudge they may spiral into overengineering or misalignment. Vibe Check provides that nudge through short reflective pauses, improving reliability and safety.

Key Features

What's New in v2.9.0 (Security & Model Refresh)

Maintenance Notice: This project is in maintenance mode and is no longer under active feature development. It remains fully functional and available under the MIT license. Community forks are welcome. For details, see the Changelog.

• Current models: Gemini 3.6 Flash, Claude Sonnet 5 / Opus 5 / Fable 5, and GPT-5.6 Sol / Terra / Luna are now the supported defaults, defined in one registry (src/utils/models.ts)
• **Native Go